Blu-Ray discs are usually classified into two types, i.e. on-groove recording discs and in-groove recording discs. The on-groove recording disc is also referred as a high-to-low disc. The in-groove recording disc is also referred as a low-to-high disc. The configurations of these two types of Blu-Ray discs will be illustrated in more details as follows.
FIG. 1A is a schematic view of a typical on-groove recording disc. As shown in FIG. 1A, a plurality of groove tracks (G) and a plurality of land tracks (L) are alternately arranged on the data layer of the Blu-Ray disc. When an optical pickup head of an optical disc drive operates, the laser beams 20 emitted by a laser diode are focused by a lens 10 of the optical pickup head, and directed to a groove track (G) through an entrance surface 30 of the Blu-Ray disc. As such, a data is recorded on the groove track (G) or read out from the groove track (G). Such a Blu-Ray disc is an on-groove recording disc.
FIG. 1B is a schematic view of a typical in-groove recording disc. As shown in FIG. 1B, a plurality of groove tracks (G) and a plurality of land tracks (L) are alternately arranged on the data layer of the Blu-Ray disc. When an optical pickup head of an optical disc drive operates, the laser beams 20 emitted by a laser diode are focused by a lens 10 of the optical pickup head, and directed to a land track (L) through an entrance surface 30 of the Blu-Ray disc. As such, a data is recorded on the land track (L) or read out from the land track (L). Such a Blu-Ray disc is an in-groove recording disc.
As can be seen from FIGS. 1A and 1B, these two types of Blu-Ray discs are distinguished by the data recording locations. That is, data are recorded on the groove tracks (G) for the on-groove recording disc, but data are recorded on the land tracks (L) for the in-groove recording disc. In this context, the groove tracks and the land tracks are defined according to the specifications of ordinary discs such as compact discs (CDs) or digital versatile discs (DVDs). Comparatively, the distance between the groove track (G) and the entrance surface 30 is smaller than the distance between the land track (L) and the entrance surface 30.
Generally, after a disc is loaded into an optical disc drive, a startup procedure of the optical disc drive is done. In the startup procedure, a servo parameter calibration task and a disc discriminating task are implemented. After the servo parameter calibration task is implemented, the optical disc drive could accurately generate a tracking error signal (TE), a focusing error signal (FE), a radio frequency signal (RF), and the like for further servo control procedures. The disc discriminating task is implemented to discriminate the type of the disc that is loaded into the optical disc drive. An example of the type of disc includes a compact disc (CD), a digital versatile disc (DVD) or a Blu-Ray disc. In addition, it may also discriminate the types of a read-only memory (ROM) disc, a recordable disc or a rewritable disc.
However, up to now, the current optical disc drive fails to effectively discriminate whether the Blu-Ray disc is an on-groove recording disc or an in-groove recording disc. In a case that the disc is discriminated as the Blu-Ray disc in the startup procedure of the optical disc drive, the optical pickup head will perform a track-locking operation according to the tracking error signal (TE) and start a reading/recording procedure.
Generally, because the current optical disc drive fails to effectively discriminate whether the Blu-Ray disc is an on-groove recording disc or an in-groove recording disc in the startup procedure, after discriminating the disc is the Blu-Ray disc, the optical disc drive will first predetermine the Blu-ray disc as a specified type of Blu-Ray disc, for example an in-groove recording disc. Then, the optical pickup head will perform the track-locking operation for locking the information pickup point of the optical pickup head on the land track and start the reading/recording procedure. Once the data or the wobble information of the Blu-Ray disc is effectively read out by the optical disc drive, the Blu-Ray disc loaded in the optical disc drive is, therefore, confirmed as the in-groove recording disc. On the other hand, once the data or the wobble information of the Blu-Ray disc fails to be effectively read out by the optical disc drive, the Blu-Ray disc loaded in the optical disc drive is, then, confirmed as an on-groove recording disc.
The conventional method for discriminating the type of the Blu-Ray disc, however, still has some drawbacks. For example, if the data of the Blu-Ray disc fails to be read out by the optical disc drive according to the first predetermined type of the Blu-Ray disc, for example an in-groove recording disc, the servo parameter calibration task of the startup process needs to be implemented again in order to obtain calibrated servo parameters according to the other type of the Blu-Ray disc, for example an on-groove recording disc. After the servo parameter calibration task is implemented, the Blu-Ray disc is determined as the on-groove recording disc. As such, the optical pickup head will perform the track-locking operation for locking the information pickup point of the optical pickup head on the groove track to read out the data or the wobble information of the on-groove recording disc.
Of course, the Blu-Ray disc loaded in the optical disc drive could be first predetermined as an on-groove recording disc, and then the above verification steps are carried out. Since the procedures of re-performing the servo parameter calibration task and implementing the track-locking operation are time-consuming, the performance of the optical disc drive is deteriorated.
Therefore, there is a need of providing a disc discriminating method to obviate the drawbacks encountered from the prior art.